4i6 HISTORY OF PERSIA CHAP> This act led to the downfall of the Durranis ; for Dost Mohamed, brother and avenger of the murdered man, took up arms and after eight years of anarchy obtained possession of the throne of Afghanistan, which his de- scendants still occupy. Herat, however, remained faithful to Mahmud and after his death to his son Kamran Mirza.1 Hostilities with Turkey, A.H. 1236-1238 (182 i-i 823).—. The last campaign fought between Persia and Turkey originated from the action of the Governor of Erzeroum, who took under his protection two nomadic tribes that had fled from Azerbaijan. Abbas Mirza made representations, but his agent was imprisoned and he was then instructed to invade the Turkish dominions. The Turks being weak, all the districts adjacent to Azerbaijan, including Kurdistan, were occupied. Farther south, the Pasha of Baghdad at- tempted to invade Persia, but was defeated by Mohamed Ali Mirza, the Shah's eldest son.2 The routed army was pursued to the gates of the city, which lay at the mercy of the Prince. But illness caused him to retreat, and upon reaching the hills he died. Meanwhile hostilities continued in the north. A Turkish detachment a thousand strong was captured by a force operating from Erivan, but was released without ransom by Abbas Mirza, who throughout showed no desire to push matters too far. The campaign ended with a battle in which the Persians, although inferior in numbers, gained a hard-fought victory. In the southern zone all military operations were stopped because the Persian army suffered from cholera, which is stated to have made its first appearance in Persia on this occasion. Peace was concluded in the end by the treaty of Erzeroum, signed in A.H. 1238 (1823). Its terms involved no terri- torial changes. The Dispute about Gokcha and its Seizure by Russia, 1825.—The treaty of Gulistan had been so vaguely worded that three districts lying between Erivan and the Gokcha 1 Kamran Mirxa had a feud with Fatteh Khan and induced his father, whose fears he excited, to give the order for his execution, which order he brought in person to Herat and executed. 2 It is stated that Mohamed Ali Mirza, when a boy, was asked by Aga Mohamed what he would do if he became Shah. • " I would kill you," was the reply* This frank expression resulted in the appointment of Abbas Mir*a, the second son, as heir-apparent.